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Laurentia basement rocks. Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America.Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and the Hebridean Terrane in northwest Scotland.
At its peak, most of North America was covered by the shallow Sauk Sea, save for parts of the Canadian Shield and the islands of the Transcontinental Arch. The stratigraphy of the Sauk sequence indicates shallow-water deposition, primarily consisting of well-sorted sandstones and clastic carbonates .
Cratons of South America and Africa during the Triassic Period when the two continents were joined as part of the Pangea supercontinent. A craton (/ ˈ k r eɪ t ɒ n / KRAYT-on, / ˈ k r æ t ɒ n / KRAT-on, or / ˈ k r eɪ t ən / KRAY-tən; [1] [2] [3] from Ancient Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two ...
The North American Cordillera extends up and down the coast of North America and roughly from the Great Plains westward to the Pacific Ocean, narrowing somewhat from north to south. It includes the Cascades , Sierra Nevada , and Basin and Range province ; the Rocky Mountains are sometimes excluded from the cordillera proper, in spite of their ...
During the Wopmay orogeny, subduction occurred as oceanic crust of the Slave Craton was subducted beneath an eastward-moving continental plate. Likewise, during the Trans-Hudson orogeny, rifting at first separated the Superior craton from the rest of the continent. Then the Superior Craton reversed its direction and the ocean basin began to close.
The Wyoming Craton is a craton in the west-central United States and western Canada – more specifically, in Montana, Wyoming, southern Alberta, southern Saskatchewan, and parts of northern Utah. Also called the Wyoming Province, it is the initial core of the continental crust of North America. The Wyoming Craton was sutured together with the ...
For North America, from oldest to youngest, they are the Sauk, Tippecanoe, Kaskaskia, Absaroka, Zuñi, and Tejas sequences. Attempts to identify equivalent cratonic sequences on other continents have met with only limited success, suggesting that eustasy (total global sea-level change) is unlikely to be the sole responsible mechanism.
Hearne Craton; Nain Craton (part of North Atlantic Craton) North American Craton (Laurentia) Rae Craton; Sask Craton; Sclavia Craton; Slave Craton, Northwest Territories, Canada (4.03–3.5 Ga) Superior Craton, Canada and northern United States (3.7–2.7 Ga) Wyoming Craton